1. Field of the Invention
The present invention is in the field of support platforms or scaffolds and pertains more particularly to an improved platform device which may be readily folded for storage or portability and erected and mounted in a variety of positions on a ladder.
2. The Prior Art
Numerous devices in the nature of ladder attachments are known, which devices are intended to be readily mounted to and demounted from ladders to provide shelf space accessible at a selected position thereon. Such devices have typically included a shelf or platform, hook means engageable with rungs of the ladder and extensible stretcher arms defining a brace spanning the distance between a portion of the platform remote from the ladder and a brace assembly engaged against and extending along the length of the ladder.
Such known devices have included a plurality of connection points disposed longitudinally of the brace whereby the stretcher may be adjustably connected to the brace so that the platform lies at a desired angle relative to the ladder.
Devices of the type described heretofore known have been bulky and incorporated a multiplicity of parts which must be relatively adjusted before the desired postitioning of the platform is attained. Moreover, the platform supporting struts in such known devices have either required an adjustment mechanism to accommodate them to the varying spans presented by particular attachment arrangements or have required that the angle defined between the struts and platform vary widely in accordance with the angular relationship of the platform to the ladder.
More particularly, where the platform was intended to be disposed against an inner leg of an "A" type ladder so as to lie between the legs of the ladder (hereinafter an inside connection) defining an included angle greater than 90.degree. between the undersurface of the ladder leg to the undersurface of the platform, the angle between the support struts and platform became very small. Accordingly, the weight which might be supported by a platform thus applied was quite limited since the point of connection between the support struts and brace lay in relative close proximity to the connection between the platform and the rungs of the ladder.
Where the devices were attached such that an acute angle was included between the undersurface of the platform and the leg of the ladder (hereinafter an outside connection), the angle between the struts and platform was increased and connection between the struts and brace effected at a distance widely displaced from the connection between the platform and the rungs.
As will be readily appreciated from the foregoing discussion, such devices required the braces to be of substantial length if both inside and outside connections were to be accomplished, making the device bulky, heavy and cumbersome to transport from job to job.